By Sarah White for MailOnline
An NHS worker has apologised for screaming 'Nazi scum' at a Donald Trump supporter who was covered in milkshake at a protest earlier today.
Siobhan Prigent took to Twitter to say she was 'very sorry' for her behaviour at the demonstration in Parliament Square.
Video footage shows Miss Prigent and a number of marchers yelling at the semi-retired grandfather before he is hit with the drink.
He tells the angry mob that he is 'here to stay' before throwing the empty cup back at them as a female police officer tries to stop it turning into a brawl.
Siobhan Prigent, pictured, has apologised for her behaviour at a London protest yesterday in which marchers yelled 'Nazi scum' at a Donald Trump supporter
Ms Prigent, a clinical trials coordinator for University College Hospital, is seen holding a placard saying: 'This episode of Black Mirror isn't funny any more! #NoThanksNazis'.
The NHS worker, who is employed by the London hospital as a contractor through her company Vlek Ltd, now faces a battle to hold on to her job.
She apologised in a now-deleted tweet: 'I am very sorry for my behaviour today. I should have protested peacefully & I didn't, & I regret that.
'I've let myself down & I do understand that fully. There are two sides to every story, but my actions were my own, & that's on me. Please leave my family & friends out of it.'
Ms Prigent can be seen holding a placard which says 'This episode of Black Mirror isn't funny any more! #NoThanksNazis'
Her apology comes after the Donald Trump supporter spoke out to reveal he was at the protest campaigning to protect democracy.
Speaking to MailOnline, the man, who refused to be identified, said he was peacefully debating with 'moderate lefties' and 'having a laugh with the majority of them' before the demonstration turned violent.
He said: 'We have to put forward how aggressive the left can be - it's not us, you know if they want to call me